The purchase of a 100 kV analytical electron microscope equipped for scanning/transmission electron microscopy (STEM), a LaB6 emitter and an energy-dispersive x-ray detector/spectrometer is proposed. The instrument will be used and operated by students and post-doctorates in bioengineering, genetics and development, anatomical sciences, microbiology, biochemistry, and others at the University of Illinois. The microscope will be employed in research projects of the following types: ultrastructural damage induced by ultrasound, receptor location of synapses, membrane biosynthesis, cellular and subcellular localization of estrogen receptors in target tissues and tumors, immuno techniques on the structure and function of the myoblast membrane, biomechanics of epithelial morphogenesis, colicin V plasmids and invasiveness of E. coli, bioengineering of photosynthetic membranes, and drug-delivery of temperature-sensitive liposomes. The proposed analytical electron microscope would make high-resolution microscopy, STEM observation of thicker sections and elemental analysis of appropriately-prepared specimens possible on a day-to-day basis, and would have a major impact on the rate of progress and scope of these investigations.